Honduras, who finished second only to Mexico in qualifying, come into the tournament on the back of a series of strong performances, including beating fellow Olympic challengers Gabon, UAE and Egypt in the past two weeks. Superbly organised in recent showings, this largely domestic-based squad could surprise some by eliminating one of the more recognisable sides in their group. European football watchers will recognise Wigan's Maynor Figueroa, while three of the squad ply their trade in the MLS.
Key Man: Anthony Lozano (Valencia B) - 19-year-old striker Lozano made his professional debut at the age of just 15, and boasts a remarkably good scoring record at youth international level. Now in Spain, his goals will be key to Honduras' chances.
Japan are another side to head into the tournament with plenty of recent preparation following the Asian Olympic qualifiers and Toulon Tournament, although they disappointed in the latter. For the main event, though, they can call upon no fewer than five Bundesliga-based players and one from the Eredivisie. Japanese football is on the rise and, even with England-based Ryo Miyaichi and Shinji Kagawa omitted, they still possess plenty of talent in attack. VVV Venlo's Maya Yoshida will marshal a talented but occasionally frail defensive line which must perform as a unit if Japan are to progress.
Key Man: Hiroshi Kiyotake (Nurnberg) - Having only recently departed Japanese football, diminutive former Cerezo midfielder Kiyotake will have a first opportunity to show a wider audience his considerable creative talents.
Morocco qualify for the tournament as the second best team in Africa, but will need to improve on mixed recent displays to progress. Dutch coach Pim Verbeek has stolen the pre-tournament headlines off his players, first by choosing not to select midfielders Adel Taarabt and Younes Belhanda, and secondly by voicing concerns that Ramadan fasting would affect his side's performance at the Games. Morocco could snatch a place in the quarter-finals, but will need to find a way to pull their talented players together as a unit.
Key Man: Zakaria Labyad (Sporting) - Previously registered to represent Netherlands, 19-year-old former PSV playmaker Labyad switched allegiance last year and will now play his first tournament in the colours of Morocco.
Spain come into tournament off the back of mixed form, having seen off Egypt and Mexico but been outgunned by a very physical Senegal side. The Spanish, coached by 2011 U-21 European Championship manager Luis Milla, will stick to the possession-based philosophy that has served the country so well at all levels in recent years, and boast several of the best young players in the European game. The Iberians are many people's favourites for gold in London.
Key Man: Javi Martinez (Athletic Bilbao) - Heavily linked with Barcelona and Bayern Munich this summer, Martinez will provide a solid midfield base from which Spain's much-vaunted forwards can build their attacks.